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arXiv · 1711.09942

Shape and fission instabilities of ferrofluids in non-uniform magnetic fields

Thibault Vieu·Clément Walter
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Abstract

We study static distributions of ferrofluid submitted to non-uniform magnetic fields. We show how the normal-field instability is modified in the presence of a weak magnetic field gradient. Then we consider a ferrofluid droplet and show how the gradient affects its shape. A rich phase transitions phenomenology is found. We also investigate the creation of droplets by successive splits when a magnet is vertically approached from below and derive theoretical expressions which are solved numerically to obtain the number of droplets and their aspect ratio as function of the field configuration. A quantitative comparison is performed with previous experimental results, as well as with our own experiments, and yields good agreement with the theoretical modeling.

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Thibault Vieu, Clément Walter. 2017-11-27. Shape and fission instabilities of ferrofluids in non-uniform magnetic fields. https://doi.org/10.1017/jfm.2018.83

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